(1) Field of the Invention
The present invention relates to a scroll type compressor suitable for an automobile air conditioner, more particularly, to an improvement thereof of the lubrication for a sealing means, bearings, and an anti-spin mechanism.
(2) Description of the Related Arts
A small size scroll type compressor suitably used for an automobile air conditioner is disclosed in Japanese Unexamined Patent Publication No. 57-62988. According to this scroll type compressor (hereinafter referred to as "compressor"), as shown in FIG. 5, a stationary scroll member 52 comprising a stationary side plate 521 and a stationary spiral body 522 is fixed to a housing half 51, and movable scroll member 54 comprising a movable side plate 541 and a movable spiral body 542 is arranged in the housing half 51 and other housing half 53. The movable scroll member 54 is engaged with the fixed scroll member 52, and thus a plurality of compression chambers 56 are formed therebetween.
Within the interior of a housing consisting of both housing halves 51 and 53, is rotatably secured a driving shaft 59 via a sealing means 57 and a main bearing 58, and a pin 60 is eccentrically mounted to the inner end of the driving shaft 59. To a base end region of the pin 60 closer to the main bearing 58 is fixed a counterweight 61, and to the other end region is fixed a drive bush 64 which supports the movable scroll member 54 by a bearing 63 so that, in association with an anti-spin mechanism, the movable scroll member is subjected only to an orbital motion and cannot spin on its own axis. Structures and functions of the counterweight and the anti-spin mechanism are described in detail such as in Japanese Unexamined Patent Publication Nos. 57-148,087 or 57-148,092.
As the spiral bodies 522 and 542 are defined by involute curves engageable with each other, volume variations occur in each compression chamber 56 formed between the scroll members 52 and 54 in accordance with the orbital motion of the movable scroll member 54, and this causes a coolant gas to flow into the compression chamber 56 through an intake port 55, which gas is successively compressed in the chamber 56 and flows out of an exit port 65 arranged centrally in the scroll members 52, 54, into a flow-out chamber 66, and finally, is fed to a refrigeration circuit (not shown) through a fluid discharge port 67.
In the compressor of the abovesaid type, the lubrication for front side mechanisms, such as the sealing means 57, the bearings 58, 63 or the anti-spin mechanism 62, is carried out by oil particles contained in the coolant gas.
According to the conventional compressor, however, the intake port 55 is provided in the housing wall closer to a rear side, i.e., to the compression chamber 56, rather than to the lubrication indispensable mechanisms in the front side area, so that the coolant gas can be directly taken into the compression chamber 56 while keeping the intake resistance at a lowest level. Accordingly, the coolant gas cannot be smoothly introduced to the lubrication indispensable mechanism, whereby it also becomes difficult to be sufficiently feed the lubricant in the coolant gas to such mechanisms, and in the worst case, a seizure or over-wear of these mechanisms may occur.
To avoid such problems, it has been proposed to provide an additional path in the housing for communicating the intake port and the sealing means (see Japanese Unexamined Utility Model publication No. 59-24992). According to this means, however, it is necessary to form, at an entrance of the additional path, a stepped portion having a complicated shape, to correctly guide a lubricant in the coolant gas into the additional path, which lowers the productivity thereof.
Thus, an object of the present invention is to provide a means for readily feeding a sufficient amount of lubricant to the mechanisms arranged in the front side region of the scroll type compressor, while avoiding an increase of the intake resistance of the coolant gas.